When oxygen is used by cells, byproducts called free radicals are naturally formed. Free radicals are molecules with a missing electron. Simply put, free radicals "want" their full share of electrons. They will take electrons from vital cell structures, causing damage and leading to disease. Antioxidants are able to donate electrons. Nutrients such as vitamin C, vitamin E, or beta-carotene are antioxidants that block some of this damage by donating electrons to stabilize and neutralize the harmful effects of free radicals.

soluble, removes free radicals from body fluids and cell structures composed mainly of water. Beta-carotene and vitamin E are fat-soluble. They seem to be active primarily in fat tissues and cell membranes throughout the body. The mineral selenium is an antioxidant that assists vitamin E.

What is the best source of antioxidants? With the possible exception of vitamin E, the best source of antioxidants is food (see Supplements: Foods, or Functional Foods? page 34). Fruits, vegetables, and grains provide a wide variety of both known and yet to be discovered antioxidants that appear to protect your body's vital functions.